A major lobbying campaign by prominent US lawmakers and former top officials in support of the anti-Iran terrorist group, Mujahedin-e Khalq Organization (MKO), has raised legal questions on the legitimacy of such top-level advocacy.

American advocates of the terrorist group, notorious for terror bombings and assassinations of scores of Iranian officials and civilians as well as siding with executed Iraqi dictator Saddam Hussein in his war against Iran in the 1980’s, have met with senior officials of President Barack Obama’s administration to push for MKO’s removal from the State Department’s terrorist list and special treatment of its members at a military camp in Iraq, The Washington Post reported Friday.

According to the report, public appearances on behalf of the MKO by such high-profile American politicians as former national security adviser to Obama administration, James Jones, former New York mayor and Republican presidential candidate Rudolph Giuliani, and ex-governor of Pennsylvania Edward Rendell had already triggered a Treasury Department probe into whether the tens of thousands of dollars received as payments for such publicity efforts violated US anti-terrorism laws.

New questions have been raised in recent weeks on whether the private meetings, conference calls and other communication with administration officials over the past year would require the MKO supporters to register as lobbyists or agents of a foreign entity.

Despite arguments by MKO advocates that they are ‘legitimately’ acting to facilitate US policy decisions, experts on lobbying regulations insist that contact with administration officials “easily meet the definition of lobbying under the Foreign Agent Registration Act, a law that has sometimes led to criminal charges,” says The Post.

The new questions, the report adds, pose the latest challenge for the MKO, which has been listed by the US State Department as a terrorist organization since 1997 and was linked to the deaths of six Americans in the 1970’s.

This is while, the anti-Iran MKO terror group and its umbrella organization, the National Council of Resistance, have been engaged in high-priced campaigning in the US for years to get off the terrorist list, including the purchasing of advertisements in The Washington Post and other major mainstream publications (at an average cost of over $50,000 per day).

A US federal appeals court, meanwhile, has given Secretary of State Hillary Clinton until October to make a decision on whether to remove the MKO from its list of international terror groups.

The Post report further reveals that the anti-Iran terror group has enlisted “some of the biggest names in US politics and national security,” including former homeland security secretary Tom Ridge, former Joint Chiefs chairman Hugh Shelton, former FBI director Louis Freeh, former UN envoys John Bolton and Bill Richardson, former US attorney general Michael Mukasey, former speaker of US House of Representatives and recent Republican presidential contender Newt Gingrich, as well as Mitchell Reiss, a former State Department official who has been one of the top foreign policy advisers to the current Republican presidential candidate Mitt Romney since 2008.

Rendell, Giuliani, Mukasey as well as Gingrich were among 16 high-profile US officials that flew to Paris last month for a pro-MKO event. In a video published by the terrorist group, Gingrich is seen bowing to MKO’s co-leader Maryam Rajavi. Afterward, according to the report, “Gingrich appealed for ‘decisive action’ by the United States on the group’s behalf.”

Furthermore, in a speech on behalf of the terrorist organization in late May, former homeland security secretary during the late George Bush administration Tom Ridge called for “regime change” in Iran, claiming, “The heart of this effort, we all believe, is to recognize democratic opposition - it is the [MKO].”

The Post report, however, goes on to quote an Iran expert as saying, “It is outright false to claim that they (MKO) are a legitimate, democracy-minded opposition group with a wide base inside Iran.”

Prominent MKO surrogates in the US have acknowledged accepting “travel expenses” from unspecific “MKO-allied groups” as well as payments of $10,000 to $40,000 for each speaking engagement. Rendell, meanwhile, has acknowledged accepting over $150,000 in expenses from “supporters” of the MKO. He also admits that before engaging in public speaking on their behalf, “he knew very little” about the terrorist group.

The US daily further reports that Treasury Department officials have interviewed several of MKO’s supporters to determine whether they violated US law by providing support to an organization on the US terrorist list. While refusing to specifically comment on the case, Treasury spokesman John Sullivan described MKO as a “designated terrorist group,” adding, “Therefore, US persons are generally prohibited from engaging in transactions with or providing services to this group.”

Other US officials familiar with the terrorist organization say, however, that the probe into paid lobbying for the MKO “remains on hold while awaiting a formal decision on its terrorist status.” Clinton, meanwhile, told US Congress in May that the State Department would favor removing MKO from its terrorist list if it complies with UN efforts to relocate its members in Iraq to a new temporary location.

US officials, according to The Post, have expressed concerns about rising tensions and an ensuing violence between Iraqi authorities and MKO members if the terrorist group members refuse to vacate the Camp Ashraf military base by the July 20 deadline.